A photoresist composition is used for semiconductor microfabrication employing a lithography process. The photoresist composition comprises an acid generator and a resin having an acid-labile group, being insoluble or poorly soluble in an aqueous alkali solution but becoming soluble in an aqueous alkali solution by the action of an acid.
US 2009/0068590 A1 discloses a resin consisting of the following structural units.

US 2010/0086873 A1 discloses a resin consisting of the following structural units.
